Clever advances in battery technology have now enabled the same tool battery and charger to be used for both home DIY and garden power tools – provided they belong to the same cordless power tool system. The Bosch 18 V Power for All, Ryobi 18 V One Plus and the Dewalt 18 V XR range are all examples of cordless power tool systems which use an interchangeable battery pack. The battery pack and charger to any one of the cordless tools in these series can be used with any other tools in the series, regardless of whether it is a cordless drill or a grass trimmer. Sometimes a battery and charger are included with the power tool and sometimes they are sold separately. Bosch 18 V, Bosch 36 V, Worx 20 V and Black & Decker are also examples of tool battery systems. Even if a battery is included when you buy a power tool it might be a good idea to buy an extra one or two spares so that you can have one on charge while you work. Having a spare battery will cut down on lost work time. Some power tools, such as circular saw use a lot of power. High-capacity battery packs with more Ah, are usually more powerful and provide a longer operating time per charge than battery packs with lower Ah values.